A segregation between cluster members and field stars in the region of the double cluster h and x Persei was done, working from proper motions and positions as kinematic random variables. A two stage process is followed overlapping each time two normal bivariate density functions. The model parameters are estimated solving a nine likelihood non linear equations system, and star membership probabilities are then found by a Baye_sian approach (Brieva and Uribe, 1990). Two different studies are made. The first one finds the h and x Persei physical members working with a 2820 star catalogue published by Lavdovskij (Lavdovskij, 1961). Figure 5 shows a good agreement between the members segregated by our method and those stars considered by Lavdovskij as sure oras the most probable members using other memberhip sources (Lavdovskij, 1965; Van Maanen, 1944; Dieckvos, 1956). A second study is made working with a larger 5504 star catalogue published by Muminov (Muminov, 1982, and http:/ /adc.gsfc.nasa.gov/adc/authors). Figure 6 shows a good agreement between the stars that Muminov considers as probable members and the members, that we segregate in the region of the double cluster.